| 摘要 |
PROBLEM TO BE SOLVED: To simultaneously and effectively control light distribution of pro-beam light distribution and counter-beam light distribution with a single implement in a road lamp equipped with a straight tube type lamp wherein the tube axial direction is arranged along the lane axis of the road. SOLUTION: In a vertical cross sectional view including a tube axis S of a fluorescent lamp 3, a reflecting mirror 4 of the road lamp 1 includes two sides 40b and 40c having a vertex angle of a triangular shape 40 wherein a side 40a confronting the fluorescent lamp 3 is opened therebetween as the section. In the reflecting mirror 4, on a section 41 perpendicular to the tube axis S of the fluorescent lamp 3, a locus described when the two sides 40b and 40c of the rectangular shape 40 are turned along a parabola 41a to the circumferential direction (b) of the fluorescent lamp 3 is a unit reflecting surface 42, and the plurality of unit reflecting surfaces 42 are arranged continuously along the tube axial direction (a), and the pro-beam light distribution and the counter-beam light distribution can be simultaneously provided. COPYRIGHT: (C)2006,JPO&NCIPI |
